Differential diagnosis of chest pain
Angina pectoris / myocardial infarction
Pericarditis
Aortic dissection
Pleurisy
Pneumothorax
Oesophageal spasm / oesophagitis
Musculoskeleta / Costochondritis
Bornholm disease – Devil’s grip, epidemic pleurodynia
Acute coronary syndrome (ACS)
Unstable angina
Angina at rest or lowering of threshold for angina
NSTEMI (Non ST elevation myocardial infarction)
Angina at rest
ECG changes – ST segment depression and T wave inversion
If troponin or CPK-MB is elevated, it qualifies for the diagnosis of NSTEMI
STEMI (ST elevation myocardial infarction)
Similar to NSTEMI, but with ST elevation on ECG – qualifies for thrombolytic therapy
Evaluate the nature of the symptoms, history of ischaemic heart disease – patients with prior history are more at risk of further episodes. Male gender and advancing age are non-modifiable risk factors. Traditional cardiac risk factors are history of diabetes mellitus, hyperlipidaemia, smoking, and family history of cardiovascular disease (last one is non-modifiable). Past or family history of cardiovascular disease include ischaemic heart disease, stroke or peripheral vascular disease. Lifestyle factors like obesity, lack of exercise, poor diet and stress also contribute.
Approach to ACS
Brief history should assess the critical aspects mentioned above.
In patients with suspected ACS, immediate ECG should be performed
Give the patient a 300 mg aspirin orally (unless contraindicated)
Give sublingual glyceryl trinitrate to act as a coronary artery vasodilator if systolic blood pressure is over 90 mmHg and pulse is less than 100 beats per minute
Insert an intravenous cannula
Give intravenous analgesia (morphine preferred) and repeat after 15 min as necessary
Give an intravenous antiemetic along with morphine to prevent associated nausea / vomiting
If the patient is bradycardic give atropine intravenously and further doses if needed
Thrombolysis to initiated at the earliest in STEMI, if emergent angioplasty is not feasible
Evaluation of angina
History is the key
Usually there are no physical signs
ECG may be normal most of the time
Blood pressure and BMI have to be recorded
Look for murmurs, especially an ejection systolic murmur of aortic stenosis which can cause effort angina
Evidence of peripheral vascular disease and carotid bruits have to be sought as these would suggest more severe associated coronary artery disease and have implications in management
Types of angina
Chronic stable angina
Nocturnal angina
Unstable angina
Variant angina (Prinzmetal’s angina)
Syndrome X (Cardiac syndrome X)
Unstable Angina
Unstable angina is defined as recurrent episodes of angina on minimal effort or at rest. It may be the initial presentation of coronary artery disease or it may represent the abrupt deterioration of a previously stable angina.
Crescendo angina, preinfarction angina and intermediate chest pain syndrome are also part of the spectrum of unstable angina. Angina is provoked more easily and persists for longer than stable angina. It may fail to respond to therapy. Pain is often associated with reversible ST segment depression on the ECG. Unless vigorously treated, up to 30% of patients may progress to myocardial infarction or death within 3 months
Prinzmetal’s / Variant Angina
Prinzmetal’s angina is caused by focal spasm of angiographically normal coronary arteries. In about two thirds of patients there is also associated atherosclerotic coronary artery obstruction. In cases where there is atherosclerotic obstruction the vasospasm occurs near the stenotic lesion. The chest pain may occur at rest or wake the patient from sleep. Variant angina may be accompanied by dyspnoea and/or palpitations
Cardiac Syndrome X
Cardiac Syndrome X is different from the metabolic Syndrome X. Symptoms and signs of angina occur in spite of angiographically y normal coronary arteries. They have evidence of ischemia in the form of a positive exercise test.
Syndrome X may be due to microvascular disease and is sometimes called microvascular angina.